Intra ventricular ambulatory implantable PV loop system

ABSTRACT

A blood pump including a housing having an inlet element, the inlet element including a distal portion coupled to the housing and a proximal portion sized to be received within at least a portion of a heart of a patient and a rotor configured to rotate within the housing and impel blood from the heart. At least one pressure sensor is coupled to the proximal portion of the inlet element.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.15/975,936, filed May 10, 2018, which granted as U.S. Pat. No.10,856,745, on Dec. 8, 2020, which is related to and claims priority toU.S. Provisional Patent Application Ser. No. 62/506,833, filed May 16,2017, entitled “INTRA VENTRICULAR AMBULATORY IMPLANTABLE PV LOOPSYSTEM,” the entirety of each of which is incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

TECHNICAL FIELD

This disclosure relates to a method and system for a blood pump havingsensors configured to measure the efficiency of the heart.

BACKGROUND

Implantable blood pumps used as mechanical circulatory support devicesor “MCSDs” include a pumping mechanism to move blood from the heart outto the rest of the body. The pumping mechanism may be a centrifugal flowpump, such as the HVAD® Pump manufactured by HeartWare, Inc. in MiamiLakes, Fla., USA. The HVAD® Pump is further discussed in U.S. Pat. No.8,512,013, the disclosure of which is hereby incorporated herein in itsentirety. In operation, the blood pump draws blood from a source such asthe right ventricle, left ventricle, right atrium, or left atrium of apatient's heart and impels the blood into an artery such as thepatient's ascending aorta or peripheral artery.

However, after such devices are implanted, it is difficult to determinewhether the diseased part of the heart is healing and functioning withinnormal parameters. That is, because the blood pump is assisting withpumping blood either from one part of the heart to another or from theheart to the lungs or the rest of the body, it is difficult to determineif, for example, the left or right ventricle is functioning normally orif it remains malfunctioning. For example, patients may undergocatheterization in a hospital setting to determine heart functionality,i.e. a PV loop analysis, however, such procedures are invasive and onlyprovide a brief snapshot of the health of the heart.

SUMMARY

Some embodiments advantageously provide a method and system for a bloodpump, including a housing including an inlet element, the inlet elementhaving a distal portion coupled to the housing and a proximal portionsized to be received within at least a portion of a heart of a patientand a rotor configured to rotate within the housing and impel blood fromthe heart. At least one pressure sensor is coupled to the proximalportion of inlet element.

In another aspect of this embodiment, the device includes a flangemember at least partially disposed around the proximal portion of theinlet element, and wherein the pressure sensor is coupled to the flangemember.

In another aspect of this embodiment, the inlet element defines a firstdiameter, and wherein the flange member defines a second diameter largerthan the first dimeter.

In another aspect of this embodiment, the device includes an ultrasonictransducer coupled to the distal portion of the inlet element.

In another aspect of this embodiment, the ultrasonic transducer iscoupled to the flange member.

In another aspect of this embodiment, the ultrasonic transducer and thepressure sensor are coupled to a microelectromechanical system (“MEMS”).

In another aspect of this embodiment, the MEMS is configured to beadhered to the flange member.

In another aspect of this embodiment, the housing further includes astator having a plurality of coils, and wherein the stator is configuredto generate a magnetic force to rotate the rotor, and wherein the statorincludes a plurality of conductors configured to couple with a powersource.

In another aspect of this embodiment, the plurality of conductors areelectrically coupled to the MEMS.

In another aspect of this embodiment, the MEMS includes a wirelesstransmitter, and wherein the ultrasonic transducer and the pressuresensor are in communication with a wireless transmitter coupled to theinlet element.

In another aspect of this embodiment, the device further includes aflange member at least partially disposed around the proximal portion ofthe inlet element, and wherein an ultrasonic sensor is coupled to theflange member.

In another embodiment, a method of measuring an efficiency of apatient's heart includes inserting an inlet element of a blood pumpwithin a chamber of the patient's heart, the inlet element including atleast one pressure sensor and at least one ultrasonic transducer. Thepressure of the chamber is measured with the at least one pressuresensor. The volume of the chamber is measured with the at least oneultrasonic transducer.

In another aspect of this embodiment, the method further includesdetermining an efficiency of the chamber of the patient's heart based onthe measurements of the pressure and volume within the chamber.

In another aspect of this embodiment, the blood pump further includes aflange member at least partially disposed around the inlet element, andwherein the at least one pressure sensor is coupled to the flangemember.

In another aspect of this embodiment, the flange member includes aproximal and a distal end, and wherein the proximal end of the flangemember is inserted within the chamber of the heart, and wherein the atleast one pressure sensor is coupled to the proximal end of the flangemember.

In another aspect of this embodiment, the at least one ultrasonictransducer is coupled to the proximal end of the flange member.

In another aspect of this embodiment, the blood pump includes a housing,and wherein the housing includes a stator having a plurality of coils,and wherein the stator is configured to generate a magnetic force torotate the rotor, and wherein the stator includes a plurality ofconductors configured to couple with a power source.

In another aspect of this embodiment, the at least one ultrasonictransducer and the at least one pressure sensor are coupled to a MEMS.

In another aspect of this embodiment, the MEMS is configured to beadhered to the flange member.

In another embodiment, a blood pump system is provided including ahousing having an inlet element, the inlet element having a distalportion coupled to the housing and a proximal portion sized to bereceived within at least a portion of a heart of a patient. A rotor isconfigured to rotate within the housing and impel blood from the heart.Two stators are included, each stator has a plurality of coils, and eachstator is configured to generate a magnetic force to rotate the rotorand includes a plurality of conductors configured to couple with a powersource. A flange member is disposed around a circumference of theproximal portion of the inlet element, the flange member includes a MEMScoupled to the plurality of conductors and adheres to a proximal surfaceof the flange member. A pressure sensor and an ultrasonic transducer arecoupled to the MEMS.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of embodiments described herein, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is an exploded view of exemplary blood pump constructed inaccordance with the principles of the present application;

FIG. 2 is front view of a portion of the assembled blood pump shown inFIG. 1 with a mounting element, flange member, and MEMS device;

FIG. 3 is a front view of the assembly shown in FIG. 1 with the MEMSdevice mounting to the MEMS device;

FIG. 4 is a Pressure-Volume (PV) loop of a cardiac cycle; and

FIG. 5 shows the device of FIG. 2 implanted within the left ventricle ofthe heart.

DETAILED DESCRIPTION

As used herein, relational terms, such as “first” and “second,” “top”and “bottom,” and the like, may be used solely to distinguish one entityor element from another entity or element without necessarily requiringor implying any physical or logical relationship or order between suchentities or elements.

Referring now to the drawings in which like reference designators referto like elements there is shown in FIG. 1 an exemplary blood pumpconstructed in accordance with the principles of the present applicationand designated generally “10.” The blood pump 10, according to oneembodiment of the disclosure, includes a static structure or housing 12which houses the components of the blood pump 10. In one configuration,the housing 12 includes a lower housing or first portion 14, an upperhousing or second portion 16, and an inlet element 18 or inflow cannula18 which includes an outer tube 18 a and an inner tube 18 b. The firstportion 14 and the second portion 16 cooperatively define a voluteshaped chamber 20 having a major longitudinal axis 22 extending throughthe first portion 14 and the inflow cannula 18. The chamber 20 defines aradius that increases progressively around the axis 22 to an outletlocation on the periphery of the chamber 20. The first portion 14 andthe second portion 16 define an outlet 24 in communication with chamber20. The first portion 14 and the second portion 16 also define isolatedchambers (not shown) separated from the volute chamber 20 bymagnetically permeable walls. The inflow cannula 18 is generallycylindrical and extends generally from the first portion 14 along theaxis 22. The inflow cannula 18 has an upstream end or proximal end 26remote from second portion 16 and a downstream end or distal end 28proximate the chamber 20.

The parts of the housing 12 mentioned above are fixedly connected to oneanother so that the housing 12 as a whole defines a continuous enclosedflow path. The flow path extends from the upstream end 26 at theupstream end of the flow path to the outlet 24 at the downstream end ofthe flow path. The upstream and downstream directions along the flowpath are indicated in by the arrows U and D, respectively. A post 30 ismounted to the first portion 14 along the axis 22. A generally discshaped ferromagnetic rotor 32 with a central hole 34 is mounted withinthe chamber 20 for rotation about the axis 22. The rotor 32 includes apermanent magnet and flow channels for transferring blood from adjacentthe center of the rotor 32 to the periphery of the rotor 32. In theassembled condition, the post 30 is received in the central hole of therotor 32.

A first stator 36 having a plurality of coils may be disposed within thefirst portion 14 downstream from the rotor 32. The first stator 36 maybe axially aligned with the rotor along the axis 22 such that when acurrent is applied to the coils in the first stator 36, theelectromagnetic forces generated by the first stator 36 rotate the rotor32 and pump blood. A second stator 38 may be disposed within the secondportion 16 upstream from the rotor 32. The second stator 38 may beconfigured to operate in conjunction with or independently of the firststator 36 to rotate the rotor 32.

Electrical connectors 41 and 43 (FIG. 1 ) are provided on the firstportion 14 and the second portion 16, respectively, for connecting thecoils to a source of power, such as a controller (not shown). Thecontroller is arranged to apply power to the coils of the pump to createa rotating magnetic field which spins the rotor 32 around the axis 22 ina predetermined first direction of rotation, such as the direction Rindicated by the arrow which is counterclockwise as seen from theupstream end of the inflow cannula 18. In other configurations of theblood pump 10, the first direction may be clockwise. Rotation of therotor 32 impels blood downstream along the flow path so that the blood,moves in a downstream direction D along the flow path, and exits throughthe outlet 24. During rotation, hydrodynamic and magnetic bearings (notshown) support the rotor 32 and maintain the rotor 32 out of contactwith the surfaces of the elements of the first portion 14 and the secondportion 16 during operation.

A first non-ferromagnetic disk 40 may be disposed within the firstportion 14 upstream from the rotor 32 between the first stator 36 andthe rotor 32 and a second non-ferromagnetic disk 42 may be disposeddownstream from the rotor 32 within the second portion 16 between thesecond stator 38 and the rotor 32. The rotor 32 is configured to rotatebetween the first disk 40 and the second disk 42 without contactingeither disk. The general arrangement of the components described abovemay be similar to the blood pump 10 used in the MCSD sold under thedesignation HVAD® by HeartWare, Inc., assignee of the presentapplication. The arrangement of components such as the magnets,electromagnetic coils, and hydrodynamic bearings used in such a pump andvariants of the same general design are described in U.S. Pat. Nos.6,688,861; 7,575,423; 7,976,271; and 8,419,609, the disclosures of whichare hereby incorporated by reference herein.

Referring now to FIGS. 2-3 , coupled to the proximal end 26 of the inletelement 18 may be a pressure sensor 44 configured to measure the bloodpressure within any one chamber of the heart. For example, the proximalend 26 may include one or an array of pressure transducers configured tomeasure the changing pressure within a particular chamber of the heartas the heart contracts and relaxes. In one configuration, the pressuresensor 44 is coupled to the most proximal end of the inlet element 18without blocking the opening in the inlet element 18 and is receivedwithin the left ventricle, although the inlet element 18 may be at leastpartially insertable within any chamber of the heart.

The pressure sensor 44 may be coupled to a flange member 46 (FIGS. 2 and3 ), as described in U.S. patent application Ser. No. 15/471,575, theentirety of which is incorporated by reference. The flange member 46functions to prevent thrombus from entering the inlet element 18. Inaddition, the flange member 46 is configured to be coupled to theproximal end of the inlet element 18 and defines a diameter larger thanthat of the inlet element 18. The most proximal end of the flange member46 is the surface of the flange member 46 that is facing the interior ofthe particular chamber in which it is inserted.

An ultrasound transducer 48 may further be coupled to the proximal end26 of the inlet element 18 or the flange member 46. The ultrasoundtransducer 48 may include one or an array of ultrasound transducersconfigured to measure the volume within a chamber of the heart as theheart contracts and relaxes. In one configuration, amicroelectromechanical system (MEMS) device 50 may be adhered to orotherwise coupled to the surface of the flange member 46 and thepressure sensor 44 and the ultrasonic transducer 48 may be integrated asarrays into the surface of the MEMS device 50. For example, the MEMSdevice 50 may be a sticker that is adhered to the flange member 46 oralternatively may be attached or etched into the surface of the flangemember 46. The MEMS device 50 may be coupled to an independent voltagesource (not shown) or the voltage source configured to power the pump10. The MEMS device 50 may further include a wireless transmitter andreceiver (not shown) such that information measured by the ultrasonictransducer 48 and/or the pressure sensor 44 may be transmitted to aremote controller (not shown) outside of the patient.

In an exemplary configuration, the most proximal end 26 of the inletelement 18 is inserted within the left ventricle of the patient. Theflange member 46 may be positioned on the proximal end 26, as describedU.S. patent application Ser. No. 15/471,575 referenced above. The MEMSdevice 50 may be adhered to the flange member 46 prior to affixation tothe inlet element 18.

The pressure sensor 44 and the ultrasonic transducer 48 be in the formof independently activated sensors in an array such that multiplemeasurements along multiple vectors may be measured. For example, thepressure sensors 44 may be included on the MEMS device 50 or directly onthe flange member 46. As the measured pressure may be variable duringthe diastole and systole cycle and may be variable based on the positionof the sensor 44 with respect to the chamber, the MEMS device 50 may beconfigured to individually activate the pressure sensors 44 of the arrayon the MEMS device to make multiple measurements either simultaneouslyor sequentially.

Similar to the pressure sensor 44, the ultrasonic transducer 48 may bein the form of an array of ultrasonic transducers 48 facing differentdirections on the MEMS device 50 to create different vectors ofmeasurement within the left ventricle, for example. Owing to theposition of the ultrasonic transducer 48 on the MEMS device 50 whenimplanted within the left ventricle and owing to the shape of the leftventricle, to measure the volume of the left ventricle, the array ofultrasonic transducers 48 may be configured to sweep across the leftventricle. In particular, such sweeping may include ultrasonictransducers 48 either having a scanning range or being movable to anglethemselves to measure the volume of the left ventricle. In oneconfiguration, a first plurality of the ultrasonic transducers 48 may betimed to measure the volume of the left ventricle during systole andanother plurality of the ultrasonic transducers 48 may be timed tomeasure the volume of the left ventricle during diastole. The combinedpressure and volume measurements may be used to produce a PV loop, asshown in FIG. 4 , to measure the efficiency of the particular chamber ofthe heart in real time.

With reference to FIG. 5 , as discussed above, in one exemplaryconfiguration, the proximal end 26 of the inlet element 18 of the bloodpump 10 is inserted within the left ventricle of the heart. The flangemember 46 is coupled to the inlet element 18 with the MEMS device 50being coupled to the surface of the flange member 46 which faces theinterior of the left ventricle such that the measurements of thepressure and/or volume within the left ventricle may be obtained.

Although the above embodiments are described with respect to a dualstator system, it is contemplated that the above sensors may be used inthe manner describe herein in axial flow pumps having a single stator,as described in U.S. Pat. No. 8,007,254 and U.S. Patent ApplicationPublication No. 2015/0051438 A1, sold under the designation MVAD® byHeartWare, Inc., assignee of the present application. Moreover, theembodiments described above are independent from the type of pump. Forexample, the sensor array described above may be positioned on anysupporting device configured to hold the pump either to the heart orwithin the heart. In one configuration, the sensor array may continue towork after the pump is removed and replaced by a plug, for example, asthe grommet/sewing ring implanted in the apex of the heart would remainin place.

It will be appreciated by persons skilled in the art that the presentembodiments are not limited to what has been particularly shown anddescribed herein above. In addition, unless mention was made above tothe contrary, it should be noted that all of the accompanying drawingsare not to scale. A variety of modifications and variations are possiblein light of the above teachings without departing from the scope of thefollowing claims.

What is claimed is:
 1. A method of measuring an efficiency of apatient's heart, comprising: inserting an inlet element of a blood pumpwithin a chamber of the patient's heart, the inlet element including atleast one pressure sensor and at least one ultrasonic transducer;measuring a pressure of the chamber with the at least one pressuresensor; and measuring a volume of the chamber with the at least oneultrasonic transducer.
 2. The method of claim 1, further comprisingdetermining an efficiency of the chamber of the patient's heart based onthe measured pressure and the measured volume within the chamber.
 3. Themethod of claim 1, wherein the blood pump further includes a flangemember at least partially disposed around the inlet element, and whereinthe at least one pressure sensor is coupled to the flange member.
 4. Themethod of claim 3, wherein the flange member includes a proximal and adistal end, and wherein the proximal end of the flange member isinserted within the chamber of the heart, and wherein the at least onepressure sensor is coupled to the proximal end of the flange member. 5.The method of claim 4, wherein the at least one ultrasonic transducer iscoupled to the proximal end of the flange member.
 6. The method of claim5, wherein the at least one ultrasonic transducer and the at least onepressure sensor are coupled to a MEMS.
 7. The method of claim 6, whereinthe MEMS is configured to be adhered to the flange member.
 8. The methodof claim 1, wherein the blood pump includes a housing, and wherein thehousing includes a stator having a plurality of coils, and wherein thestator is configured to generate a magnetic force to rotate a rotor, andwherein the stator includes a plurality of conductors configured tocouple with a power source.
 9. The method of claim 1, wherein the atleast one ultrasonic sensor includes an array of independentlyactivatable ultrasonic sensors facing different directions.
 10. Themethod of claim 1, wherein the at least one pressure sensor includes anarray of independently activatable pressure sensors.
 11. The method ofclaim 1, wherein the chamber is a left ventricle of the heart.
 12. Amethod comprising: measuring, by at least one pressure sensor, apressure in a chamber of a heart of a patient, wherein an inlet elementof a blood pump includes the at least one pressure sensor; andmeasuring, by at least one ultrasonic transducer, a volume of thechamber, wherein the inlet element includes the at least one ultrasonictransducer; and determining an efficiency of the chamber of the heartbased on the measured pressure and the measured volume within thechamber.
 13. The method of claim 12, wherein the at least one ultrasonictransducer includes an array of ultrasonic transducers facing differentdirections, and wherein measuring the volume of the chamber comprisesmeasuring the volume along multiple sensing vectors.
 14. The method ofclaim 12, wherein the at least one ultrasonic transducer includes anarray of ultrasonic transducers facing different directions, and whereinmeasuring the volume of the chamber comprises: measuring, using a firstplurality of ultrasonic transducers of the array of ultrasonictransducers, the volume of the chamber at a first time; and measuring,using a second plurality of ultrasonic transducers of the array ofultrasonic transducers, the volume of the chamber at a second time. 15.The method of claim 14, wherein the first time is during systole and thesecond time is during diastole.
 16. The method of claim 12, wherein theat least one pressure sensor includes an array of pressure sensorsfacing different directions, and wherein measuring the pressure in thechamber comprises measuring the pressure along multiple sensing vectors.17. The method of claim 12, wherein the at least one pressure sensorincludes an array of pressure sensors facing different directions, andwherein measuring the pressure comprises: measuring, using a firstplurality of pressure sensors of the array of pressure sensors, thepressure in the chamber at a first time; and measuring, using a secondplurality of pressure sensors of the array of pressure sensors, thepressure in the chamber at a second time.
 18. The method of claim 17,wherein the first time is during systole and the second time is duringdiastole.
 19. The method of claim 12, wherein the chamber is a leftventricle of the heart.